Math Is Fun Forum

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: An interesting equation

Hi anonimnystefy;

Did that make life easier? Have you been able to solve that?

Not all equations are solvable by hand methods. Polynomials are the simplest
functions and after the 4th degree you can no longer solve them by algebraic
means. Your equation has a non linear step function. These are best solved by iteration, in short a computer
method.

If this is some book problem then I would expect there to be some
weird trick that is going to make everything right. But if this is a real problem and
I had to solve it I would not waste anytime with algebra. Just telling you what works.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: An interesting equation

well actually i could use the fact that alpha is greater or equal to zero and less than one but i don't know what to do then.

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“Here lies the reader who will never open this book. He is forever dead.
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: An interesting equation

Hi;

Is it a book problem? Or did this come out of someone's head?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: An interesting equation

it is a book problem.

---

“Here lies the reader who will never open this book. He is forever dead.
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

gAr

Member

Registered: 2011-01-09

Posts: 3,482

Re: An interesting equation

Hi,

I thought of a method,
It would be wonderful if there is any property of floor that simplifies this even further.

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"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense"  - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: An interesting equation

Hi gAr;

I did something like that for him in an earlier post. As a congruence you can solve it by iteration. I think he wants some manipulation that is going to zero in on the answer.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

gAr

Member

Registered: 2011-01-09

Posts: 3,482

Re: An interesting equation

Hi bobbym,

I thought you told you worked backwards there, so I was trying to figure out how you derived that.

A direct formula which gives the answer is difficult to find, I guess, because the number of solutions vary?

But from the congruence method, we may narrow in the search.
Solve for x without the floor, and substitute for k which gives the x nearby.

---

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense"  - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: An interesting equation

Hi gAr;

My solution does not count. He had me working on a different problem. In mine it is + 13 floor(x), I think he changed that later.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

gAr

Member

Registered: 2011-01-09

Posts: 3,482

Re: An interesting equation

Hi,

Yes, he told that in 25th post.
Anyway, not much change, just a change of sign is required for your answer.

I'm interested to know which book is that. I never came across a problem like this, involving floor.

---

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense"  - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: An interesting equation

Hi;

I have not seen too many either. I will ask him if I see him first.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

gAr

Member

Registered: 2011-01-09

Posts: 3,482

Re: An interesting equation

Okay.

---

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense"  - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."